FWIW, I found a Tweet dating back to Jan 8 that was in reply to somebody who tweeted a Youtube livestreamed dogsledding race: https://twitter.com/Cami5320/status/1479893333480599555

One more reason to use youtube-dl / yt-dlp then?

Never seen before but it kinda makes sense.. if I was YT?

A bad actor could sign up, start a livestream and start spamming the link to gain thousands of viewers. But of course this also fairly limits the ability of a community to start a stream and garner following.

Tweet was deleted

It's working for me, here's the picture of the tweet in case it is locally blocked: https://i.imgur.com/dh1kU1q.png

Anyways it looks like censorship is thriving like never before. I wonder what' up.

I think it's more likely that this is an abuse-prevention scheme rather than a censorship scheme. If so, "what's up" is that the Internet is full of assholes, and preventing assholes from wasting your money and ruining things for everyone else is very hard to do perfectly, especially when you provide a free service with anonymous sign-up.

One way to do so is to limit the privileges of accounts without much history.

Which would be "fine" if Google was even remotely transparent in its definition of "without much history".